Internaut: Take over WiFi spectrum to improve communications
- By Shawn McCarthy
- Nov 03, 2004
Shawn P. McCarthy
Have you ever thought of WiFi signal interference as a contract issue rather than a technical problem? Changing your mindset may be a good way to eliminate some of the noise on your wireless networks.
As government agencies deploy multiple wireless networks throughout their buildings, they often run into several types of signal interference. Impediments such as ceramic tile, thick concrete and metal walls can often be overcome by installing additional wireless hubs. But the problem of electrical or radio interference isn't as easy to solve.
When you manage a network of several 802.11 WiFi hubs, external signal noise can come from several sources. These include wireless telephones, which run at 2.4 GHz, as well as microwave ovens and Bluetooth devices. Any of these devices operating near your WiFi hubs can degrade or knock out a signal.
One way to fight back is for an IT department to declare that it 'owns' the WiFi spectrum within a building. Anyone operating a device found to interfere with a network signal would be required to remove the device.
But it's not always easy to enforce such a declaration. Charles Bartel, director of network services at Carnegie Mellon University, recently shared a story about an airport that attempted to do so. But businesses operating in the airport challenged the declaration. The Federal Communications Commission eventually supported the challengers, saying that WiFi is an unlicensed part of the radio spectrum, so no one can claim to own the space.
But Bartel said universities have had better luck with similar declarations. They often are able to limit the presence of competing devices in dorms and other university-owned campus areas by making it part of their contract with incoming students.
Government agencies can take a tip from universities. They often control the buildings where they are located. IT departments that want to eliminate other devices need to make their case to building managers. If everyone agrees, competing devices can be phased out.
In cases where government offices occupy shared spaces, it's more complicated. Mangers may need to work with landlords to set priorities for WiFi, and it may be wise to make WiFi signal control part of new lease agreements. Landlords or building managers can then help set expectations throughout a building and enforce rules when problems occur.
If all participants are equally protected through cooperative agreements that cover overlapping wireless zones, people should be willing to get on board.
At the edges of shared spaces, where IT managers can't control neighbors' activities that may affect a wireless signal, other adjustments may be necessary. These may include shielding hubs on one side or adjusting packet size. (Smaller packets are sometimes a way to avoid microwave interference.) Whatever the nature of interference'from inside or out'planning is essential.Shawn P. McCarthy is senior analyst and program manager for government IT opportunities at IDC of Framingham, Mass. E-mail him at firstname.lastname@example.org.
Shawn McCarthy, a former writer for GCN, is senior analyst and program manager for government IT opportunities at IDC.